Interior LPD
2021 International Energy Conservation Code
C405.3.2Interior lighting power allowance.
The total interior lighting power allowance (watts) for an entire building shall be determined
according to Table C405.3.2(1) using the Building Area Method or Table C405.3.2(2) using the
Space-by-Space Method. The interior lighting power allowance for projects that involve only portions
of a building shall be determined according to Table C405.3.2(2) using the Space-by-Space
Method. Buildings with unfinished spaces shall use the Space-by-Space Method.
Revise as follows:
TABLE C405.3.2(1) INTERIOR LIGHTING POWER ALLOWANCES: BUILDING AREA
METHOD
BUILDING AREA TYPE LPD (w/ft
2
)
Automotive facility 0.75 0.719
Convention cente
r
0.64 0.629
Courthouse 0.79 0.729
Dining: bar lounge/leisure 0.80 0.729
Dining: cafeteria/fast food 0.76 0.679
Dining: family 0.71 0.639
Dormitory
a, b
0.53 0.509
Exercise cente
r
0.72 0.699
Fire station
a
0.56 0.559
Gymnasium 0.76 0.729
Health care clinic 0.81 0.759
Hospital
a
0.96 0.919
Hotel/Motel
a, b
0.56 0.519
Library 0.83
Manufacturing facility 0.82
Motion picture theate
r
0.44 0.419
Multiple-family
c
0.45
Museum 0.55
Office 0.64 0.609
Parking garage 0.18 0.169
Penitentiary 0.69 0.649
Performing arts theater 0.84 0.809
Police station 0.66 0.609
Post office 0.65 0.629
Religious building 0.67 0.649
Retail 0.84 0.769
School/university 0.72 0.689
Sports arena 0.76 0.699
BUILDING AREA TYPE LPD (w/ft
2
)
Town hall 0.69 0.659
Transportation 0.50 0.539
Warehouse 0.45
Workshop 0.91 0.859
For SI: 1 watt per square foot = 10.76 w/m
2
.
a. Where sleeping units are excluded from lighting power calculations by application of Section R404.1,
n
the area of the sleeping units nor the wattage of lighting in the sleeping units is counted.
b. Where dwelling units are excluded from lighting power calculations by application of Section R404.1,
n
the area of the dwelling units nor the wattage of lighting in the dwelling units is counted.
c. Dwelling units are excluded. Neither the area of the dwelling units nor the wattage of lighting in the d
w
units is counted.
TABLE C405.3.2(2) INTERIOR LIGHTING POWER ALLOWANCES: SPACE-BY-SPACE
METHOD
COMMONSPACETYPES
a
LPD(
w
Atrium
Less than 40 feet in height 0.
4
Greater than 40 feet in height 0.
6
Audience seating area
In an auditorium 0.
6
In a gymnasium
In a motion picture theater
In a penitentiary 0.
6
In a performing arts theater 1.
1
In a religious building
In a sports arena 0.3
Otherwise
Banking activity area 0.
6
Breakroom (See Lounge/breakroom)
Classroom/lecture hall/training room
In a penitentiary 0.
8
Otherwise 0.
7
Computer room, data center 0.9
Conference/meeting/multipurpose room 0.9
COMMONSPACETYPES
a
LPD(
w
Copy/print room 0.3
Corridor
In a facility for the visually impaired (and not used primarily by the staff)
b
In a hospital 0.
7
Otherwise 0.
4
Courtroom 1.2
Dining area
In bar/lounge or leisure dining 0.
8
In cafeteria or fast food dining 0.
4
In a facility for the visually impaired (and not used primarily by the staff)
b
1.2
In family dining 0.
6
In a penitentiary 0.
4
Otherwise 0.
4
Electrical/mechanical room 0.
4
Emergency vehicle garage 0.5
Food preparation area 1.
0
Guestroom
c, d
Laboratory
In or as a classroom 1.1
Otherwise 1.3
Laundry/washing area 0.5
Loading dock, interior
Lobby
For an elevator 0.6
In a facility for the visually impaired (and not used primarily by the staff)
b
1.
6
In a hotel
In a motion picture theater 0.2
In a performing arts theater 1.2
Otherwise 0.
8
Locker room
Lounge/breakroom
COMMONSPACETYPES
a
LPD(
w
In a healthcare facility 0.
4
Otherwise 0.5
Office
Enclosed 0.
7
Open plan 0.
6
Parking area daylight transition zone 1.059
Parking area, interior 0.1
Pharmacy area 1.
6
Restroom
In a facility for the visually impaired (and not used primarily by the staff
b
1.2
Otherwise 0.
6
Sales area 1.
0
Seating area, general 0.2
Security Screening General Areas 0.639
Security Screening in Transportation Facilities 0.929
Security Screening Transportation Waiting Area 0.559
Stairwell 0.
4
Storage room 0.3
Vehicular maintenance area 0.
6
Workshop 1.2
BUILDINGTYPESPECIFICSPACETYPES
a
LPD(
w
Automotive (see Vehicular maintenance area)
Convention Center—exhibit space 0.
6
Dormitory—living quarters
c, d
0.5
Facility for the visually impaired
b
In a chapel (and not used primarily by the staff) 0.
7
In a recreation room (and not used primarily by the staff) 1.
7
Fire Station—sleeping quarters
c
Gaming Establishments
High Rollers Area 1.679
Slots 0.539
COMMONSPACETYPES
a
LPD(
w
Sportsbook 0.819
Table Games 1.089
Gymnasium/fitness center
In an exercise area 0.9
In a playing area 0.
8
Healthcare facility
In an exam/treatment room 1.
4
In an imaging room
In a medical supply room 0.
6
In a nursery 0.9
In a nurse’s station 1.1
In an operating room 2.2
In a patient room
c
0.
6
In a physical therapy room 0.9
In a recovery room 1.2
In a telemedicine room 1.439
Library
In a reading area 0.9
In the stacks
Manufacturing facility
In a detailed manufacturing area 0.
8
In an equipment room 0.
7
In an extra-high-bay area (greater than 50 feet floor-to-ceiling height)
In a low-bay area (less than 25 feet floor-to-ceiling height) 0.86
In a high-bay area (25–50 feet floor-to-ceiling height)
In a low-bay area (less than 25 feet floor-to-ceiling height)
In an extra-high-bay area (greater than 50 feet floor-to-ceiling height) 1.42 1.3
6
Museum
In a general exhibition area
In a restoration room 1.1
Performing arts theater—dressing room 0.
4
COMMONSPACETYPES
a
LPD(
w
Post office—sorting area 0.
7
Religious buildings
In a fellowship hall 0.5
In a worship/pulpit/choir area 0.
8
Retail facilities
In a dressing/fitting room 0.5
Hair salon 0.649
Nail salon 0.749
In a mall concourse 0.
8
Massage space 0.809
Sports arena—playing area
For a Class I facility
e
2.9
For a Class II facility
f
2.
0
For a Class III facility
g
1.3
For a Class IV facility
h
Sports arena—Pools
For a Class I facility 2.199
For a Class II facility 1.469
For a Class III facility 0.989
For a Class IV facility 0.589
Transportation facility
Airport Hanger 1.359
At a terminal ticket counter 0.51 0.3
9
In a baggage/carousel area 0.3
In an airport concourse 0.2
Warehouse—storage area
For medium to bulky, palletized items
For smaller, hand-carried items
For SI: 1 foot = 304.8 mm, 1 watt per square foot = 10.76 w/m
2
.
a. In cases where both a common space type and a building area specific space type are listed, the buildi
n
specific space type shall apply.
b. A ‘Facility for the Visually Impaired’ is a facility that is licensed or will be licensed by local or state aut
h
for senior long-term care, adult daycare, senior support or people with special visual needs.
c. Where sleeping units are excluded from lighting power calculations by application of Section R404.1,
n
the area of the sleeping units nor the wattage of lighting in the sleeping units is counted.
d. Where dwelling units are excluded from lighting power calculations by application of Section R404.1,
n
the area of the dwelling units nor the wattage of lighting in the dwelling units is counted.
e. Class I facilities consist of professional facilities; and semiprofessional, collegiate, or club facilities with
for 5,000 or more spectators.
f. Class II facilities consist of collegiate and semiprofessional facilities with seating for fewer than 5,000
spectators; club facilities with seating for between 2,000 and 5,000 spectators; and amateur league an
d
school facilities with seating for more than 2,000 spectators.
g. Class III facilities consist of club, amateur league and high school facilities with seating for 2,000 or fe
w
spectators.
h. Class IV facilities consist of elementary school and recreational facilities; and amateur league and high
s
facilities without provision for spectators.
C405.3.2.1Building Area Method.
For the Building Area Method, the interior lighting power allowance is calculated as follows:
1. For each building area type inside the building, determine the applicable building area type and the all
o
lighting power density for that type from Table C405.3.2(1). For building area types not listed, select t
h
building area type that most closely represents the use of that area. For the purposes of this method, a
n
shall be defined as all contiguous spaces that accommodate or are associated with a single building are
2. Determine the floor area for each building area type listed in Table C405.3.2(1) and multiply this area
b
applicable value from Table C405.3.2(1) to determine the lighting power (watts) for each building are
a
3. The total interior lighting power allowance (watts) for the entire building is the sum of the lighting po
w
each building area type.
C405.3.2.2Space-by-Space Method.
Where a building has unfinished spaces, the lighting power allowance for the unfinished spaces shall
be the total connected lighting power for those spaces, or 0.2 watts per square foot (10.76 w/m
2
),
whichever is less. For the Space-by-Space Method, the interior lighting power allowance is
calculated as follows:
1. For each space enclosed by partitions that are not less than 80 percent of the ceiling height, determine
applicable space type from Table C405.3.2(2). For space types not listed, select the space type that mo
s
represents the proposed use of the space. Where a space has multiple functions, that space may be divi
separate spaces.
2. Determine the total floor area of all the spaces of each space type and multiply by the value for the spa
c
Table C405.3.2(2) to determine the lighting power (watts) for each space type.
3. The total interior lighting power allowance (watts) shall be the sum of the lighting power allowances f
o
space types.
Reason:
The values in Table C405.3.2(2) are interlinked with the values in Table C405.3.2(1). The building
values [Table C405.3.2(1)] are comprised via aggregating the individual space values [Table
C405.3.2(1)].
These proposed values were developed via a multi-step analysis:
More than 150 data sheets from more than 10 lighting manufacturers data sheets were
compiled.
The 2021 data sheets indicate increased efficacy compared to products from 2018 and 2019.
At least 2/3 of the data sheets compared were the same fixture from 2019 and 2021. For
most of the directly tracked products, the efficacy of these fixtures had increased in this
time.
Lighting conditions were modeled for each of the spaces using these 2021 efficacy values
and the resultant lighting power density values were these proposed values.
These proposed values represent a 4 - 5% reduction (based on a straight average of
changes) compared to the previous version. These proposed values are similar to those that are
being considered by ANSI/ASHRAE/IES Standard 90.1.
Cost Impact:
The code change proposal will neither increase nor decrease the cost of construction.
There is no cost increase for this proposal. The proposed reduced lighting power density values are
based on manufacturer data sheets. Manufacturers have improved the performance of their products
and these values are based on their improvements. As stated in the rationale, more than 150
products were evaluated. Between 2018 and 2021, these fixtures became more efficient. Cost
changes between 2018 and 2021 are not from changes in efficacy, but inflation, supply chain, and
material constraints.
